End-to-End Testing 101: Definitions, Benefits, Methods, and Metrics

End-to-end testing is important to ensure the quality of the product you'll be shipping. Especially in this competitive market, where the end-user can be very choosy, it’s necessary to perform end-to-end testing of applications to provide a good user experience.

To help you better understand this notion, in this article, I will delve into the basic tenets of end-to-end testing, its benefits, metrics, method and how to measure success.

What Is End-to-end Testing?

End-to-end (E2E) testing is a technique that tests the entire software product from beginning to end to ensure the application flow behaves as expected. In other words, it helps define the product system dependencies and ensures all integrated pieces work together as expected. Eventually, the main purpose of this testing type is to test from the end user’s experience by simulating the real user scenario and validating the system under test and its components for integration and data integrity.

Benefits of E2E Testing

End-to-end testing has been more reliable and widely adopted because of these following benefits:

• Expand test coverage
• Ensure the correctness of the application
• Reduce time to market
• Reduce cost
• Detect bugs

E2E Testing Lifecycle

An end-to-end testing lifecycle consists of four components: test planning, test design, test execution, and results analysis.

• Test planning: Specifies key tasks, associated schedule, and resources
• Test design: Test specifications, test case generation, risk analysis, usage analysis, and scheduling tests
• Test execution: Executes test cases and documents testing results
• Results analysis: Analyzes test results, evaluate testing, and perform additional testing if necessary

End-to-end Testing Methods

Horizontal E2E testing

A commonly used method occurring horizontally across the context of multiple applications and easily takes place in a single ERP (Enterprise Resource Planning) application. Here’s an example. A Web-based application of an e-commerce system includes accounts, product inventory status, and shipping details.

Vertical E2E testing

This method refers to testing in layers, meaning that tests happen in sequential, hierarchical order. To ensure quality, each component of a system or product is tested from start to finish. Vertical testing is often used to test critical components of a complex computing system which does not typically involve users or interfaces.

Metrics for End-to-end Testing

Some of the many metrics used for E2E testing are:

• Test Case Preparation Status: Used to determine the specific position of the test cases that are under preparation, compared to planned test cases.
• Test Progress Tracking: Test progress should be tracked on a weekly basis. This step will provide regular details of test completion percentage, such as passed/failed, executed/unexecuted, valid/invalid test cases, and so on.
• Defects Status and Details: It gives a weekly percentage of open and closed defects. Also, weekly defect distributions are based on severity and priority.
• Environment Availability: The actual number of operational hours and hours scheduled per day for testing.

When to Apply End-to-End Testing

There are many scenarios to apply end-to-end testing. Here’s an example:

Before testing, designers and developers create a list of which UI, functions or features that need to be performed. Data flow should be tracked between systems to find dependencies, flaws, and inaccuracies. Teams also have to prepare the conditions – factors that may change any interface options – before testing.

E2E testing is regularly conducted on finished products and systems, making each review a test of the completed system. A second test will take place if the system does not output what is expected or if a problem is found. In this case, the team will have to record and analyze the data to determine the issue’s origin; then fix and re-test them.

Conclusion

Overall, end-to-end testing is one of the most effective ways to ensure end-user application performance. Due to the benefits it brings, end-to-end testing has been more reliable and widely adopted, and as such, it’s now a good time for you to start learning this testing procedure if you have not done so.